Fish feed discharging apparatus

ABSTRACT

An apparatus for discharging fish feed, including a feed portioning device (1-3) connected to a probe device (5), which is at least partially immersed in water and excitable by fish for activating the portioning device such as to discharge a quantity of feed to the fish. The probe device contains an element (8) sensitive to sound and/or pressure waves and which reacts for pushes against the probe device achieved by the fish, and accordingly sends signals to an electrical device (4) for activating the portioning device (1-3).

DESCRIPTION TECHNICAL FIELD

The present invention relates to an apparatus for discharging fish feed,including a feed portioning device and a probe device connected thereto,at least partially immersed in water, and which is excitable by fish foractivating the portioning device such as to discharge a quantity of feedto them.

BACKGROUND ART

Apparatus of the kind mentioned above are already known, e.g. from theU.S. Pat. Nos. 3,688,743, 3,730,142 and 4,270,489, the German publishedspecification Nos. 2 310 382 and 2 441 936 and the Norwegian patent No.128 514.

The apparatus according to the U.S. Pat. Nos. 3,688,743, 3,730,142 and4,270,489 each include a pendulum dependent in the water. A bodyconnected to the pendulum and mounted to cover an opening in a feedcontainer uncovers a part of this opening when the pendulum is displacedby the fish from a straight-down dependent position, such that a givenquantity of feed is discharged.

The greatest disadvantage with these apparatus is that a relativelylarge force is required to swing the pendulum, resulting in that theapparatus can only be used for relatively large fish. If the apparatusare used in conjunction with fish breeding in lakes, rivers or the like,currents and waves also cause the pendulum to be swung with undesiredfeed discharge as a result.

The apparatus according to the German published specification Nos. 2 310382 and 2 441 936 include pendulums dependent in water in aquaria. Whenthe pendulums are acted on by fish, a current circuit is closed so thata relay is excited to provide discharge of feed from a containersuspended above the water surface.

Even if just as large a force is not required for swinging the pendulumsaccording to both the last-mentioned publications, very small fishcannot achieve this pendulation. Furthermore, the pendulums would beaffected by currents and waves, resulting in undesired feed discharge,if the apparatus were used for fish breeding outdoors. Since thecontacts included in the current circuit are placed without protectionand in the vicinity of the water they are oxidized rapidly, and theoperational reliability of the apparatus is lowered. The apparatusaccording to the Norwegian patent No. 128514 includes a feed containerwith an opening through which feed is discharged with the aid of aconveyer screw coupled to an electric motor, which is started when acurrent circuit is closed by a sprung breaker arm being caused to engagea contact when bait attached to a line dependent from an arm is taken bya fish.

This latter apparatus also requires relatively large force, andfurthermore the force must be applied in a given direction for the armto close the circuit. This means that the apparatus cannot be used inbreeding smaller fish. If the spring in the breaker arm is selected sothat it is very weak, a minor force can indeed cause the circuit to beclosed when a smaller fish takes the bait, but the apparatus will bevery sensitive to currents, waves and winds at the same time, and cantherefore be triggered even when there are no fish in the vicinity ofthe apparatus. The placing of the contact and breaker arm and theirnearness to the water also results in operational problems.

DISCLOSURE OF INVENTION

One object of the present invention is to remove the disadvantages withpreviously known apparatus and provide a simple and operationallyreliable apparatus which can be triggered by small fish as well, andwhich is insensitive to currents, waves and winds and similarenvironmental factors which can unintentionally trigger it.

This object is achieved by the invention having been given thecharacterizing features disclosed in the claims.

DESCRIPTION OF FIGURES

The sole FIGURE on the drawing schematically illustrates, partially insection, an apparatus in accordance with the invention.

PREFERRED EMBODIMENT

A fish feed portioning container 1 is suspended over a water surface V.The container 1 can, for example, be of the kind illustrated in theSwedish patent No. 73 14519-5 and contains a vibrator 2, whichdischarges the feed from the container via a plate 3 when the vibratoris supplied with electrical signals from an electrical central unit 4connected to an unillustrated current source, the unit being connectedto the container 1 via a cord 16 in which the tension has been unloaded.

A probe device generally denoted by the numeral 5 is partially immersedin the water directly under, or a short distant from, the container 1,The probe device 5 depends freely at one end of a tensionally unloadedcord 6. The other end of the cord is connected to the unit 4. The probedevice includes a stiff casing 7, the upper portion of which forms thetensional unloading means. An element 8, sensitive to pressure, ismolded fast at the middle of the upper part.

The lower portion of the casing 7 is screwed to its upper portion, andprovided with a tube 10 at its lower end. The tube is terminated by adiaphragm 9, e.g. a plastic or rubber fingerstall which is sufficientlystiff so as not to be collapsed by the water pressure outside thehousing.

The element 8 may be a microphone, a piezoelectrical, capacitive,inductive or other pressure-sensitive element.

The operation of the inventive apparatus will now be described togetherwith the components included in the electrical unit 4.

When a fish pushes against the diaphragm 9, sound and/or pressure wavesare formed in the tube 10 and housing 7, these waves being propagated,even if the push is very weak, to the sensitive element 8, which thengives a signal via conductors in the cord 6 to the unit 4. The signal isamplified in an amplifier 12 to a suitable level before it is taken to alowpass filter 13 where high frequencies are filtered away. The signalis then taken to a comparator 14 with a level sensing circuit which, fora sufficiently strong signal, sends a control signal to a timer 15, thelatter thus being activated, and, for a time interval set on the timerbeforehand, sends a pulse to the vibrator 2 for discharging feed fromthe container 1 during this interval.

Although it has been found in trials that air is a good transmissionmedium from membrane 9 to the pressure-sensitive element 8, other mediafor this purpose can be envisaged.

The element 8 only takes up pressure and/or sound waves caused bymomentary pushes against the diaphragm 9. If knocks against the casing 7or the tube 10 are propagated as pressure and/or sound waves to theelement 8, these are filtered away in the lowpass filter 13 since theyhave a frequency, due to the selectional material in the casing andtube, that differs from the frequency of the signals generated by pushesagainst the diaphragm, and thus lie outside the frequency range for thesignals passed through by the filter. Pressure and/or sound wavesgenerated by currents and waves in the water can indeed be transplantedto the element via the membrane 9 if they are sufficiently heavy andhave a short-duration character, but they are not transplanted assignals to the portioning container 1, since these waves have adifferent frequency that is incorrect compared with the one generatedfor a direct rapid push against the diaphragm 9, and therefore nosignals are passed from these waves.

It is possible to adjust the sensitivity of the inventive apparatus tothe size of the fish which are bred, by providing the amplifier 12 witha potentiometer (not shown). If the bred fish are small and thus canonly achieve weak pushes against the diaphragm 9, the potentiometer isset so that the signals from the element 8 are amplified to a suitablelevel before they are taken to the filter 13.

Even if only one embodiment of the invention has been described aboveand illustrated on the drawing, it should be understood that theinvention is not limited to this embodiment but only by what isdisclosed in the claims.

I claim:
 1. Apparatus for discharging fish feed, including a fish feedportioning device (1-3) with a probe device (5) connected thereto and atleast partially immersed in water, the device (5) being excitable byfish for activating the portioning device such as to discharge aquantity of feed to the fish, characterized in that the probe device (5)includes an element (8) sensitive to sound and/or pressure waves, saidelement reacting for pushes against the probe device achieved by thefish and accordingly sending signals to an electrical device (4) foractivating the portioning device (1-3).
 2. Apparatus as claimed in claim1, characterized in that the electrical device (4) is arranged toactivate the portioning device (1-3) only when the probe device (5) issubjected to momentary pushes.
 3. Apparatus as claimed in claim,characterized in that the sensitive element (8) is enclosed in awaterproof casing (7) in the probe device (5).
 4. Apparatus as claimedin claim 3, characterized by a tube (10) attached to the casing (7), thetube having a lower end provided with a diaphragm (9) the outside ofwhich is actuable by the fish, and the inside of which forms a wall in achamber inside the casing and tube in communication with the sensitiveelement (8).
 5. Apparatus as claimed in claim 4, characterized in thatthe diaphragm (9) is flexible and consists of rubber or plastics.